What the Anesthesiologist Should Know before the Operative Procedure
Liposuction is a popular elective cosmetic procedure whereby subcutaneous adipose tissue is reduced in targeted locations in order to improve a patient’s aesthetic appearance. Depending on the magnitude of adipose tissue to be removed in any given operation, the surgery may be considered minor or major. The choice of anesthetic often depends upon the magnitude of the planned surgery, with potential options including local, monitored anesthesia care, regional, and general.
The anesthetist must be particularly cognizant of risks associated with tumescent infiltration solutions administered by the surgeon, including complications from fluid shifts, local anesthetic toxicity, and iatrogenic epinephrine excess. Surgeons may seek to perform liposuction procedures in hospitals, office-based clinics, or ambulatory centers the setting may depend upon the magnitude of the procedure, the choice of anesthetic, the patient’s overall health, the anticipated postoperative recovery needs, and other factors.
1. What is the urgency of the surgery?
What is the risk of delay in order to obtain additional preoperative information?
Liposuction surgery is elective surgery. Patients should be optimized, and there should be a low threshold for delaying or cancelling surgery if additional preoperative evaluation is indicated.
Emergent: Not applicable
Elective: There is no medical risk inherent in delaying a liposuction procedure.
2. Preoperative evaluation
Special attention is warranted for any issues related to the cardiovascular, pulmonary, renal, hepatic, endocrine, or psychological status of the patient.
Medically unstable conditions warranting further evaluation include almost any perturbance from the patient’s baseline health status since patients should be clearly optimized for elective cosmetic surgery.
Delaying surgery may be especially warranted if the patient has any cardiovascular, pulmonary, renal, hepatic, endocrine, or psychological conditions that have not been optimized.
3. What are the implications of co-existing disease on perioperative care?
Liposuction is intended to target local areas of adipose excess for aesthetic purposes, and is not intended as a weight-loss procedure per se. However, patients seeking liposuction may have generalized obesity, a condition which can be associated with cardiovascular disease, obstructive sleep apnea, diabetes mellitus, and other coexisting diseases. Patients with significant medical issues, including ASA III and ASA IV patients, may be poor candidates for elective cosmetic surgery due to increased risk of perioperative complications.
a. Cardiovascular system
Acute/unstable conditions: Liposuction is an elective cosmetic surgery which should be postponed if the patient has acute, unstable, or sub-optimized cardiovascular problems.
Baseline coronary artery disease or cardiac dysfunction, including valvular disease – Goals of management: The patient’s functional status should be assessed, including the existence of angina or dyspnea. Blood pressure should be well-controlled. An electrocardiogram should be reviewed. An echocardiogram or stress test may also be helpful, as might documentation from a prior evaluation by a cardiologist. The tumescent solution typically used in liposuction procedures (1) contains epinephrine and (2) may be administered in large volumes, both of which may be poorly tolerated in patients with baseline cardiovascular disease.
COPD and reactive airway disease: Many liposuction procedures can be done under local or MAC anesthesia, and it may be prudent to avoid unnecessary general anesthesia, airway manipulation, and mechanical ventilation in patients with pre-existing pulmonary disease.
Smoking is associated with poor wound healing, hypercoagulable state (risk of thromboembolism), and pulmonary disease. Smoking is not an absolute contraindication to liposuction, but patients should generally be advised to quit preoperatively and also to refrain from smoking postoperatively as their wounds heal.
Patients with significant renal disease are poor candidates for elective cosmetic surgery. Large liposuction procedures may involve the administration of significant volumes of crystalloid-based tumescent infiltrate solutions, and concomitant fluid and electrolyte disturbances may be poorly tolerated in patients with renal dysfunction. Further, disturbances of medication metabolism may result in prolonged recovery from anesthesia.
Patients with significant hepatic disease, especially if coagulopathic, are probably inappropriate candidates for elective cosmetic surgery. Lidocaine, which is administered in high doses via commonly used tumescent fluid formulations during liposuction, has prolonged elimination times in patients with hepatic dysfunction. Therefore, there may be an increased risk of local anesthetic overdose.
Obese patients may suffer from diabetes or glucose-intolerance, which is associated with poor wound healing and increased infection risk. Conditions that increase the risk of perioperative complications may pose important ethical dilemmas with regard to the appropriateness of performing elective cosmetic surgery.
Thyroid conditions are common and may not involve any meaningful additional risk as long as the patient’s condition is being properly managed preoperatively. Symptoms of poorly controlled hyperthyroidism could be exacerbated by the routine inclusion of epinephrine in liposuction tumescent solutions.
Anxiety and depression — and the routine medications (such as selective serotonin reuptake inhibitors) used to treat those conditions — are not contraindications to liposuction. However, some patients seeking elective cosmetic surgery may suffer from more severe psychiatric conditions, including body dysmorphic disorder, eating disorders, and related conditions. These patients may falsely believe that liposuction represents a “cure” in such cases, surgery should be postponed pending the results of outpatient psychiatric consultation.
h. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
4. What are the patient's medications and how should they be managed in the perioperative period?
Patients are typically advised to continue their routine medications during the perioperative period, including on the morning of surgery. Exceptions include herbal supplements, vitamin E, and fish oil supplements, which are typically stopped one week prior to surgery. Anti-inflammatories, such as ibuprofen and NSAIDs, are typically held three days prior to surgery. Anticoagulants vary based on the particular agent for example, coumadin (warfarin) is typically held for five days prior to surgery.
Other over-the-counter medications are typically avoided on the morning of surgery, such as vitamins, minerals, calcium supplements, and potassium supplements. Insulin-dependent diabetics tend to be poor candidates for elective cosmetic surgery, but if such a patient were to proceed with liposuction then it would be prudent to administer half of the standard morning dose of long-acting insulin, schedule the patient as the first case of the day, and institute frequent blood glucose checks.
i. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
j. What should be recommended with regard to continuation of medications taken chronically?
Cardiac medications, including beta-blockers and anti-arrhythmics, should be continued, although ACE-Is and ARIIBs are sometimes held due to an association with intraoperative hypotension.
Pulmonary medications, including asthma medications, should be continued.
Metformin should be held due to risk of lactic acidosis. Long-acting insulin should be administered in a half-dosage on the morning of surgery, which periodic glucose monitoring during the perioperative period. Diuretics should be continued due to risk of fluid overdose associated with liposuction.
Neurologic medications, including anti-seizure drugs, are typically continued.
Anti-platelets and anti-coagulants
These drugs are typically held preoperatively, although continuation of a small dose of aspirin may be justified in some cases.
Anti-anxiety and depression medications are typically continued, although MAO-Is may be discontinued before surgery.
k. How to modify care for patients with known allergies –
If possible, avoid medications and classes of medications to which the patient has a known allergy. Regardless, the anesthetist must always be vigilant for signs and symptoms of allergic reaction and/or anaphylaxis (including but not limited to nausea, rash, hives, tachycardia, hypotension, and bronchospasm) and also be prepared to promptly and aggressively treat the reaction (typically with antihistamines such as diphenhydramine and ranitidine, anti-inflammatories such as hydrocortisone, and other medications such as epinephrine and albuterol).
l. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
Patients with current or prior employment in the health care field may be at higher risk of adverse reaction to perioperative latex exposure.
m. Does the patient have any antibiotic allergies?
Beta-lactam antibiotics such as cephalosporins are common choices for liposuction procedures. Common alternatives in patients who report beta-lactam allergy (including penicillin allergy) include the lincosamide drug clindamycin or the glycopeptide antibiotic vancomycin.
n. Does the patient have a history of allergy to anesthesia?
Malignant hyperthermia (MH)
Documented history of MH: Avoid all trigger agents such as succinylcholine and volatile inhalational agents:
Proposed general anesthetic plan:
Intravenous induction and total intravenous anesthetic (options include propofol infusion, ketamine infusion, benzodiazepines, opiods, and others.) Nitrous oxide is also an option as part of a balanced anesthetic. A ‘clean’ anesthesia circuit and machine (one that has not been exposed to volitiles or one that has been flushed clean according to manufacturer recommendations) should be utilized.
Ensure MH cart availability:
The cart should include a sufficient quantity of non-expired vials of dantrolene (2.5 mg/kg IV dissolved in sterile water). Additional qualified personnel should be notified in advance that they may be called upon to help if an emergency occurs and be called immediately if one should occur. If MH is diagnosed (presence of triggering agent, rising end-tidal CO2, hyperthermia, tachycardia, tachypnea, muscle rigidity), then the offending agent (succinylcholine and/or inhaled volatile anesthetic) should be discontinued immediately, and dantrolene and 100% oxygen administered. The patient should also be aggressively cooled to reduce hyperthermia, hyperventilated to reduce acute hypercarbia, and treated for respiratory and metabolic acidosis. Fluids and diuretics should be used with the goal to maintain urine output at 2 mL/kg/hr. Important lab studies include ABG, CPK, electrolytes, calcium, and coagulation studies. Hyperkalemia should be treated aggressively to avoid arrhythmias. Arrangements must be made to admit the patient to an ICU setting. Dantrolene should be continued until body temperature and hypercarbia normalize.
Family history or risk factors for MH:
In the absence of a highly compelling need to use a triggering agent, prudence dictates that the same precautions should be utilized in these patients as in patients with a documented history of MH.
5. What laboratory tests should be obtained and has everything been reviewed?
Healthy young patients may not need preoperative laboratory tests, especially for minor cases. Routine labs should be considered for more complicated patients or operations.
Common laboratory normal values will be same for all procedures, with a difference by age and gender.
Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?
The quantity and location of adipose tissue to be targeted by the surgeon is a crucial determinant of the duration of the operation and feasibility of alternatives to general anesthesia. A discussion of patient positioning and any special concerns with regard to positioning injury should also be included in a preoperative discussion with the surgeon.
a. Regional anesthesia
Benefits: Depending on the region of the body being targeted for liposuction, an epidural or spinal could provide with patient with excellent intraoperative relief from pain.
Drawbacks: The risk of local anesthetic overdose from large quantities of surgical tumescent solution may be compounded by local anesthetic administered via an epidural catheter. Also, the risk of fluid overload from large quantities of surgical tumescent solution may be compounded by intravenous fluid administered to prevent and treat hypotension secondary to neuraxial block. A lengthy surgical time may realistically preclude the use of regional anesthesia.
Peripheral nerve block
Benefits: Depending on the region of the body being targeted for liposuction, a peripheral nerve block could provide with patient with excellent intraoperative relief from pain.
Drawbacks: The risk of local anesthetic overdose from large quantities of surgical tumescent solution may be compounded by local anesthetic administered used for a peripheral block.
b. General Anesthesia
Benefits: Provides predictable and excellent operating conditions, allowing the surgeon to better focus on the procedural technique itself. Ideal for large aspirate liposuction cases of prolonged duration.
Drawbacks: Masks signs and symptoms of local anesthetic overdose. Typically requires airway manipulation.
Airway/oxygenation concerns:Large liposuction procedures increase risk of potential fluid overload and pulmonary edema.
c. Monitored Anesthesia Care
Benefits: Especially suitable for minor cases of limited duration in cooperative patients. Patients are able to report signs and symptoms of local anesthetic overdose.
Drawbacks:Risk of sedation overdose and respiratory depression concurrent with an ‘unsecured’ airway. Should a patient tolerate the procedure poorly, there is a risk of needing to abort the procedure or needing to convert unexpectedly to general anesthesia.
Benefits: The large quantities of local anesthetic contained in the tumescent solution may itself constitute a sufficient anesthetic in some cases.
Drawbacks:Qualified personnel must be available to increase the level of sedation if the patient cannot tolerate ‘local-only’ anesthesia, or else the procedure could prove psychologically traumatic for the patient
6. What is the author's preferred method if anesthesia technique and why?
What prophylactic antibiotics should be administered?
Cefazolin 1-2 g IV. If beta-lactam allergy, clindamycin 600-900 mg IV or vancomycin 1 g IV. (SCIP 2007)
What do I need to know about the surgical technique to optimize my anesthetic care?
The extent of the planned procedure – including the quantity of adipose tissue to be targeted and the duration of the planned procedure – has important implications as to whether the patient might tolerate a MAC anesthetic, and as to the appropriate postoperative disposition.
What can I do intraoperatively to assist the surgeon and optimize patient care?
Although strict muscle paralysis is not necessary, unwanted patient movement will complicate surgical technique.
What are the most common intraoperative complications and how can they be avoided/treated?
i. Specific to procedure: fluid overdose
Numerous techniques and modifications exist, but the standard method for body-contouring is called tumescent, suction-assisted liposuction, in which large volumes of crystalloid, containing very dilute lidocaine and epinephrine, is injected into the subcutaneous tissue, followed by suctioning of the aspirate via cannula. Certain techniques allow for very large quantities of aspirate (more than 4 Liters). In these cases, intravenous fluids should be minimized in order to minimize the risk of fluid overload. Fluid overload due to the use of a large volume of tumescent solution can precipitate pulmonary edema, and respiratory and congestive heart failure.
ii. Specific to procedure: lidocaine overdose
Dosage: Lidocaine is typically included in the tumescent (or “wetting”) solution utilized during liposuction, at a concentration of 0.05%-0.1% (0.5 g/L-1 g/L). Lidocaine is useful for intraoperative and postoperative pain control. Classically, the maximum dose of lidocaine is reported at 7mg/kg. Much higher doses are administered during liposuction, with maximum safe doses reported in the range of 35-55mg/kg.
Reasons for the higher allowable threshold include: slowed absorption due to diluted concentrations of lidocaine, epinephrine-related vasoconstriction, minimal vascularity of adipose tissue, and sequestration of lidocaine in adipose tissue attributable to lipophillicity. Risk of overdose may persist many hours into the postoperative period as lidocaine levels remain elevated, and in fact may not peak until five to ten hours after the conclusion of the procedure. The risk of overdose is increased in patients taking medications that inhibit the liver’s cytochrome P450 system, and also in patients who otherwise have significant hepatic impairment.
Overdosage: Signs and symptoms include metallic taste in the mouth, ringing in the ears, numbness around the lips, and more nonspecific feelings such as lightheadedness and fatigue. Central nervous effects include tremors, seizures, and coma. Ultimately respiratory depression, arrhythmias, and cardiac arrest may occur.
iii. Specific to procedure: epinephrine overdose
Dosage: Epinephrine is typically included in the infiltrate at a concentration of approximately 1:1,000,000 (1 mg/L). Epinephrine is useful because its vasocontractive properties limit bleeding and also limit the potential toxicity of lidocaine (while prolonging the duration of pain relief). The maximum dose is reported be 0.7 mg/kg, although higher doses have been reported.
Overdosage: Epinephrine is associated with tachycardia and hypertension. These effects could be particularly problematic in a patient with pre-existing hypertension, cardiac arrhythmias, cardiovascular disease, or conditions such as hyperthyroidism or pheochromocytoma. Cardiopulmonary complications from epinephrine overdose include hypertensive crisis, myocardial ischemia, arrhythmias, and heart failure. The concurrent use of halothane anesthesia and epinephrine is further associated with arrhythmias.
b. If the patient is intubated, are there any special criteria for extubation?
Standard extubation criteria apply, with extra attention to the possibility of fluid overload in a prolonged case featuring large volumes of tumescent solution.
c. Postoperative management
What analgesic modalities can I implement?
Pain in the immediate post-operative period may be minimal due to the prolonged efficacy of tumescent solution containing lidocaine and epinephrine. Acetaminophen and opioids may also be useful.
What level of post-operative bed acuity is appropriate?
Liposuction is often performed on an outpatient basis. Patients should be observed post-operatively until routine discharge criteria are met. Some patients may warrant overnight observation, especially in the case of a prolonged, large aspirate liposuction case, or if patients have coexisting disease or have experienced intraoperative complications.
What are common postoperative complications, and ways to prevent and treat them?
Toxicity from lidocaine and/or epinephrine contained in the infiltrate solution is a possibility. As described above, the patient should be monitored for signs and symptoms, and doses should be tracked and limited, and specific side effects should be treated with targeted therapy (i.e. benzodiazepines for a seizure secondary to local anesthetic toxicity, or beta-blockers for excessive sympathetic activity).
Fluid overload is a possible sequelae when large volumes of aspirate are used in major liposuction cases. Intravenous fluid should be minimized, and fluid balance should be monitored throughout the case. Surgeons should be encouraged to record the amounts of fluid infiltrate and fat aspirate during the case. Patients should be monitored for evidence of pulmonary edema, which might require treatment with diuretics, prolonged postoperative monitoring, or further workup and intervention.
Other complications include deep venous thrombosis and pulmonary embolism, including fat embolism. Deep venous thrombosis (DVT) is a risk of any surgery, especially longer procedures. Compression devices and/or pharmacologic DVT prophylaxis may be utilized. The patient should be monitored postoperatively for evidence of pulmonary embolism, a life-threatening condition that is best treated by early diagnosis and aggressive treatment.
Traumatic perforation of an organ or major blood vessel, as well as pneumothorax, can be caused by the liposuction cannula. Seromas, infection, skin hyperpigmentation, paresthesias, and patient dissatisfaction with the aesthetic outcome are other notable complications associated with liposuction.
What's the Evidence?
Kucera, IJ. “Liposuction: contemporary issues for the anesthesiologist”. J Clin Anesth. vol. 18. 2006. pp. 379-87.
Lynch, DJ, Iverson, RE. “ASPS Committee on Patient Safety. Practice advisory on liposuction”. Plast Recontr Surg . vol. 113. 2004. pp. 1478
Matarasso, A, Levine, SM. “Evidence-based medicine: liposuction”. Plast Reconstr Surg.. vol. 132. 2013. pp. 1697-705.
Iverson, RE, Pao, VS. “Liposuction”. Plast Reconstr Surg. vol. 121. 2008. pp. 1-11.
Flynn, T, Narins, R. “Preoperative evaluation of the liposuction patient”. Dermatol Clin. vol. 17. 1999. pp. 729-34.
Commons, GW, Halperin, B, Chang, CC. “Large-volume liposuction: A review of 631 consecutive cases over 12 years”. Plast Reconstr Surg. vol. 108. 2001. pp. 1753
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- What the Anesthesiologist Should Know before the Operative Procedure
- 1. What is the urgency of the surgery?
- What is the risk of delay in order to obtain additional preoperative information?
- 2. Preoperative evaluation
- 3. What are the implications of co-existing disease on perioperative care?
- a. Cardiovascular system
- b. Pulmonary
- c. Renal-GI:
- d. Neurologic:
- e. Hepatic:
- f. Endocrine:
- g. Psychiatric:
- h. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
- 4. What are the patient's medications and how should they be managed in the perioperative period?
- i. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
- j. What should be recommended with regard to continuation of medications taken chronically?
- k. How to modify care for patients with known allergies -
- l. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
- m. Does the patient have any antibiotic allergies?
- n. Does the patient have a history of allergy to anesthesia?
- 5. What laboratory tests should be obtained and has everything been reviewed?
- 6. What is the author's preferred method if anesthesia technique and why?
- What prophylactic antibiotics should be administered?
- What do I need to know about the surgical technique to optimize my anesthetic care?
- What can I do intraoperatively to assist the surgeon and optimize patient care?
- What are the most common intraoperative complications and how can they be avoided/treated?
- i. Specific to procedure: fluid overdose
- ii. Specific to procedure: lidocaine overdose
- iii. Specific to procedure: epinephrine overdose
- a. Neurologic:
- b. If the patient is intubated, are there any special criteria for extubation?
- c. Postoperative management
- What's the Evidence?